Nepeta
by Garrae
Summary: When Castle decides that Beckett's had a stressful week and buys her a present to cheer her up, matters do not proceed precisely as he had hoped. Caskett Cats universe, pre-children. Two shot. Strongish T. Cats Universe 5.5
1. Chapter 1

**Chapter 1**

"I got you a present," Castle said happily.

Beckett, in her preferred Onyx-form for curling up in Castle's excellently comfortable lap or draping herself over his shoulder, looked up, saw nothing except a small container, flicked her tail disdainfully and returned to the far more important task of washing a paw. She'd had a headache all day and now that she was home, with the delightful prospect of having the following day off, being Onyx soothed it.

"C'mon. Change back." He picked her up, plopped her on his shoulder and sat down on the couch, stroking her silky fur. "You'll like it."

She purred, and snuggled furrily into his neck. She didn't want to change back. _Castle_ should change, and then they could be very happily feline together: her slim Siamese nestled into his much larger, heavier Maine Coon: their black fur merging and their tails entwined. That would be a much better plan than some small box containing an indeterminate substance. Or he could keep stroking her, or even better, play with her ears or brush her, to leave her in a post-orgasmic haze. That would solve the headache. She mewed commandingly.

Castle put her down and bounced off the couch, leaving her behind. He was _not allowed_ to do that. She jumped down, and stalked after him to the kitchen, where he was putting the kettle on. What? He was reaching for a _teapot_? No, no, no. She drank coffee. Tea was for other people. And now he was opening his little box, which contained _tea leaves_? That was _not_ a present. That was a mistake.

She stalked back to the couch and concentrated on washing her paws, extending and retracting her claws to ensure that they were properly polished and functional. There was the clonk of a tray on the table. Steam rose from the teapot's spout, and wound its way through the air to her sensitive cat nose. She drew in the scent. It was...interesting. Appealing. She padded on to Castle's lap, to take a deeper breath.

"C'mon," he said again. "I got it specially. I had to go all the way across town to a specialist tea shop for it. It's called Nepeta tea. You'll like it."

That did sound intriguing, and he'd gone to a lot of trouble, and, well, how difficult was it to make him happy? She stood up on her back paws, butted her head into his neck, and changed, to end up sitting on his lap and neatly nestled in.

"Nepeta?" she queried.

"It's a herbal tea. Supposed to be good for headaches, and you've had a pretty stressful week, so I thought it might help. Mother used to swear by teas to cure headaches – on other people. She used Bloody Marys."

Beckett snickered, then snuggled in further and kissed his neck. "That's really sweet, babe. I'll give it a moment to cool down, and then try it." She looked at the tray. "Aren't you having any?"

"No. I got it specially for you – and I tried a tiny bit of it in the shop and it was nice but I thought you needed it more, so I got myself some camomile tea." The small kettle clicked off. "I'll just infuse mine."

She – reluctantly – slid off his knee and allowed him to make his own small pot of tea. She thought he was a little expectant, but Castle was ridiculously fond of giving her silly little gifts as often as he could get away with it, and he always wanted to see her reaction to them. (She didn't give him silly little gifts. Instead, every so often, she bought him flowers: showy peonies, when she thought he needed a little flamboyance boost; heartsease if he was a little unhappy or had received an unkind review; crimson roses just because she loved him with all her heart. They were rarely without flowers somewhere in the loft.)

She waited for him to return, and then curled back into his lovely broad chest, enclosed in a lovely strong arm, and perfectly, felinely, content with life. Castle hummed happily, and poured his own tea.

She sniffed deeply – it had a really nice scent – took a cautious sip – a burnt tongue was so _limiting_ – and regarded the teacup with astonishment. "This is really nice." Castle smiled happily. She took another deep breath and a mouthful, and savoured it. It was very good indeed. She snuggled more firmly into Castle. He was delightfully snuggly, and she should definitely take full advantage of his snuggliness, accompanied by another mouthful of tea.

In fact, she should just slither back into his lap. After all, it was right there, beckoning her. It looked very comfortable. And if she were in his lap, he'd be much more kissable. His lips looked very kissable, suddenly: even more so than usual. Conveniently, he put his cup down, and she instantly slid on to his knee and tucked her head into his shoulder. Even more conveniently, she could smell his quite delicious cologne, and nibble at his neck, and then leave a trail of little peck-kisses all the way up to his jaw. She should spend lots of time kissing Castle. Lots and lots and lots of time.

"Why aren't you petting me?" she pouted, pettishly. "I like being petted." He should be stroking her hair, and tucking it behind her ears, and generally fussing over her and fondling her and just plain _petting._

"Sure," he said easily. "C'mere." He glided one large hand over her hair, down to her back, in just the way she liked best, and she arched her back into the touch and half purred, even in Beckett-guise. She also wiggled a little. "Do you want your tea?" She certainly did. She liked this new tea.

"Yes, please. It's really good."

Castle handed her the cup, and she drained it and put it down. It was warm all the way down to her tummy... huh? She never used the word _tummy_. It should only ever be applied to children, and there certainly weren't any of them around. Good. The existence of children would definitely cramp her style. Thinking of which, why was she leaning on Castle's extortionately expensive, but stylish, button down when she could be nicely nestled against his nice warm skin? She opened a button or two, and laid her cheek on said nice warm skin. Quite without her conscious input, a few more buttons opened, which left a nice space into which her hand fitted perfectly. It slid round his middle, and he squeaked.

"You tickled me! That's not nice!"

Beckett giggled. Indignant Castle was always very funny. She tickled again, just to see what would happen, and then had another idea. She became Onyx, turned round, and wriggled her tail into the space in the shirt. Castle positively squealed.

"Stoppit!" He most unfairly plucked her out, disarranging her tail fur, and plopped her back the other way round. She stretched up to lie on his shoulder, and used her tail to tickle his nose. He sneezed, and squeaked more. "Stop tickling me!" She would. If properly encouraged. He hadn't petted her properly and she wanted petted, and fondled, and ear-caressed. She flicked her ears at him. "Oh, I see." About time, Castle. He stroked around her ears, and she settled down and purred happily until his clever, naughty fingers reduced her to a cat-shaped puddle of satisfied sensuality.

Still. She wanted rather more, and suddenly she knew exactly how to acquire it. Her tail trailed insinuatingly over Castle's stomach, and wriggled just under his belt. His eyes widened. "Beckett..." he whimpered, "what are you doing?"

"If you don't know," she husked, changing back, "then I'd better show you." Her fingers replaced her disappearing tail. She wondered why she'd never teased him with her tail before. It had certainly had a most interesting effect. She changed back again, suddenly. How had that happened? She hadn't meant to.

"Ow!" Castle yowled. "Claws!"

She pulled her paw out of his pants. She certainly hadn't meant to extend claws _there_. She changed back to Beckett.

"Sorry," she said. "But if you took them off, it wouldn't have happened." _What?_ She hadn't meant to say that. Castle stared at her. She stared back, with her best glare, used fingers to open his pants and changed back to Onyx. Her tail drifted over him.

"I thought we agreed same form only?" he squeaked.

Rules were for other people, though she certainly didn't want mixed form sex. Eurgh. Some indecent teasing, however... Her tail flickered. Castle whimpered, again. She stopped tickling his assets and pushed herself into his lap, squirming on to her back and rolling over and over.

"Beckett, are you okay – oh my God."

She'd leapt down and was now happily rolling round the floor, mewing loudly. Why had she never done this before? It was as good as ear fondling or brushing. She rolled some more. The rug felt _wonderful_ on her back. She lay on her back, wiggled orgasmically, and waved all four paws in the air. Despite her open invitation, Castle monumentally failed to tickle her tummy – hold on a moment, there was that word again... oh, who cared? She wiggled around the rug again, and then spotted Castle, still sitting stump-like on the sofa. She wanted her tummy tickled and her ears petted and her fur brushed.

She wouldn't mind some more of that excellent tea, either. And after that, Castle could do something useful and strip. Slowly. After _that_ , she was sure she could think of something for them to do – oh look, she could see a moth! She bounded over to it, chasing it round the room but never quite catching it, which was totally unfair.

Oooohhhh! Tail! She followed the end of the tail around, but every time she tried to jump on it, it ran away. That was totally unfair, too. It should stay put and be pounced upon. Tail-chasing was _fun_. Playtime! Even if it was unfair that the tail wouldn't play nicely.

Equally unfair, Castle had caught her and stopped her playing. She didn't get nearly enough time to play, and he was spoiling it. Well, she had a solution to that too. He shrieked as she turned into her panther and growled at him.

"Don't growl," he said. "I wanted to pet you, and you're _growling_ at me. It's not nice."

Oh. Petting. Yes. She'd wanted petting – ooohhhh, a bit of his shirt was flapping! She pounced on it.

"Yee-ouch!"

Oh. Ooops. Oh dear. She looked at him penitently, still a full-size panther, and licked the scratch in his side to make it better. She was tired. Maybe a nice nap would do her some good. She lay on the couch with her black head on Castle's lap and closed her eyes.

Castle stared at the sleeping panther and wondered what the hell had just happened to her. She'd drunk her tea, which he'd bought because she'd been really stressed lately and the shop had said it was excellent for headaches, and then she'd gone totally insane in all three forms, and now she was asleep.

Rather too late, he Googled the name of the tea.

Oh, _shit_. He should kill himself now, because Beckett was going to do it for him just as soon as she had worked out what had gone on. Oh, _shit_. He'd accidentally got her high. Oh God, he was so dead. He'd never thought... and she was human when she drank it... and oh God he was dead.

He'd given Beckett catnip tea.

Oh God.

He hadn't _meant_ to. He really, really hadn't.

She wasn't going to believe him. Oh God. When she woke up there was going to be hell to pay – or Beckett, which was worse. Oh God.

It occurred to Castle that if he were his full size male panther, Beckett probably couldn't kill him. At least, not if he covered her and pinned her down. In any form, she couldn't defeat his massive panther. If he stayed human, she could kill him in dozens of ways from all three forms – even Onyx could kill him, with a well-aimed slash of her claws, if he didn't get her wrapped up first.

Oh God. He'd doped her. He frantically looked up the effects of catnip – and _why_ had the tea store not identified it properly? It wasn't _fair_ that they'd hidden its true name – and found that Beckett was pretty much a textbook case. Oh God.

He looked down at the sleeping still-panther Beckett, and frantically wondered what to do to save the situation – and his testicles, and probably his life. Even so, he automatically stroked her silky fur, which was soothing. She purred in her feline sleep, and twitched. He cuddled her, and wished very strongly that she were in Onyx-form.

A while later, Beckett's panther eyes opened: hazy and definitely not (yet) murderous. She made an odd noise, as if she were trying to talk: neither a purr nor a growl, certainly not a miaow. Panthers, Castle had learned, did not miaow.

"Hey," he said softly. Her head shook, as she tried to clear it. Suddenly there was human-Beckett, with her head in his lap.

"Urrrggghhhh," she said. "What happened?"

"You fell asleep," Castle said very disingenuously. "Are you okay?"

"Urrgh," she said again, and sat up, shaking her head some more. Castle waited nervously.

Slowly, remembrance slunk across her face, and she shrank into herself and blushed violently. "What did I do?" she wailed. "I never behave like that." She turned into Onyx, and jumped down on to the floor to hide out of sight and wash her paws frantically, radiating sheer embarrassment.

"It was cute," Castle said without thinking. "You're really cute when you're playful." Onyx's paw washing intensified. He leaned over to check where she was. "C'mon. Come back here and be petted." Onyx didn't move. She'd also stopped washing her paws, and her ears and tail were twitching – oh God, that pattern of twitching always indicated intense thought. He stood up, under the guise of putting the tea tray in the kitchen. If he were quick, he'd make it to the bathroom – which locked – before he was found out.

He got two steps. Onyx growled, and suddenly the panther was between Castle and the bathroom. He walked to the kitchen, stalked by Beckett-panther, and was then herded back to the couch. She didn't look at all friendly, and her claws flexed. He sat down, hurriedly. The panther changed back to Beckett, who drilled him with a most unwelcome glare.

"What did you do?" she interrogated. He cringed. "You put something in my tea, didn't you? That's why you were so keen on me drinking it. You spiked it."

"I" – she rolled over him before he could say _didn't_.

"It's just like you made fun of me with t-shirts. Well, if you think that's a funny joke you'll like this one even better – I'm going home."

She slammed out the door before he managed to open his mouth, and by then it was too late to change to stop her. He grabbed his jacket and dashed after her, crashing down the stairs and out into the street.

She wasn't there. He couldn't even see a space in the crowds where she would have forced her way through them. Castle, unwilling to leave the quarrel – no, Beckett's unjustified jump to a conclusion which simply wasn't _fair_ – to fester, took himself to her apartment and slithered through the cat-flap. She had plenty of books and coffee to keep him occupied until she arrived.

Beckett had exited Castle's building, slipped into the alley close by and changed to her cat again, leaving herself invisible in the gloom. She sneaked through the crowds till she reached another convenient alley, returned to her human self, and caught the subway to Central Park. Some soothing squirrel-murdering was just what she needed.

She disappeared into the dark by the entrance, and Onyx skulked into the dusk. In an hour or less, the panther would come out to play, safe from passing joggers. Lowlifes would not be safe from the panther, however. She growled, and the local wildlife took off for safety. Onyx curled up at the base of a tree, and waited for darkness to fall, eyes shut, tail curled in.

Her calm position didn't translate to her mood. It was typical. He couldn't resist his dumb _research_ whether it suited her or not. First t-shirts, and now tea. Well, she might research some _T_ as well. Torture, for a start. She cringed again at her earlier behaviour, even if she had been doped. She'd really thought he'd stopped that sort of dumbass prank. She hunkered down again, and gave thanks that cats didn't cry.

Not long later, a trail of disembowelled squirrels and pigeons showed her infuriated path. Sirens squealed as those few lowlifes who inhabited Central Park on a cold March night found something a lot more dangerous than they were, and didn't like it one bit. Fortunately, the Central Park precinct was delighted to assist them to a safe place, though its facilities were basic and the locks were on the outside of the rooms.

Hours later, the panther's blood lust and Beckett's furious temper were sated. Her hurt and disappointment were not.

* * *

Castle waited, reading. A third book finished, he looked for a fourth and realised that it was long past midnight. It didn't reassure him. He hadn't eaten: he didn't want to eat. He simply wanted Beckett to show up so he could make her listen to him. He understood where she was coming from, but she was _wrong_. He'd never deliberately have got her high. Never.

He had an idea. He was tired, anyway. He tucked the book back into the stuffed shelves, switched off the lights, and changed into his Maine Coon form, curling up on the couch. In the dark, he'd be invisible. He reckoned Beckett would go straight to her bedroom when she eventually came in – and what was she doing, anyway? Probably the precinct – that was her go-to refuge. He should have gone there... she couldn't kill him or change in public. He tucked his head into his paws, his wide tail around his body, and dozed.

He was woken by Beckett coming in, and, as he'd predicted, going straight to her bedroom: hard, fast clicks on the wooden floors. Castle-cat didn't move. He'd give her some time to get into bed and then...um...take steps. He plotted carefully: first, pad silently into her room, then, still as a cat, curl up next to her; if she woke, become the massive panther until she would listen to him. She only _said_ she slept with a gun. She didn't really – at least, she never had when he was there.

His sensitive ears picked up the rustle of her quilt, fading into even breathing. He waited for several more minutes, then, quite certain she was asleep, ghosted into her bedroom. He changed to the panther, and surveyed his prey.

Oh, _fuck_. She'd been crying. Guilt stabbed him. He _hated_ when she cried, and hated more that she only ever did it when she thought he wouldn't find out. Of course he always did find out, but... she hid from him, rather than leaning on him. Six months in, and (even though she'd admitted she loved him already) she was good at sharing happiness but no good at all at sharing anything that might indicate weakness: still fighting to pretend that she was invincible. She didn't need to. He loved her anyway: all her little foibles and fretfulnesses, and he'd love her even if she sometimes needed support. He'd love her whenever she needed support.

* * *

 _Thank you to all readers and reviewers._

 _More insanity in the Cats universe, prompted (again) by Bahamut Slayer. Two shot._


	2. Chapter 2

**Chapter 2**

He prowled up on to the bed, and lay down next to her, curling his tail over her hips, forgetting that he'd intended to be the cat instead of the huge panther. In her sleep, she mewed, which was reassuring, and snuggled, which was more so: pressing into his furry warmth. She liked to snuggle in, whether feline or human.

Usually. Snuggling hadn't exactly been top of her mind when she'd stormed out. He stayed still, and waited, dozing again. Beckett turned over in her sleep – and jerked awake and away.

Castle put a huge paw over her, to bring her back. She swiped at him, but forgot she was human. It had as much effect on him as a gnat would have had. He rumbled at her, with a hint of a growl. She tried to turn her back on him, and the rumble became more growly. When she stopped trying to turn, he patted gently at her and rubbed his black head into her neck, very softly.

"Go away," she said, pushing at him. He didn't move an inch away, but his tail slid over her. "I don't want you here."

Castle changed back. "I didn't know about the tea."

"Yeah, right. Just like you 'didn't know' about the natural fibres. Fool me once..." She turned over. "Go away. I need to sleep."

"I didn't. It was called Nepeta Tea. The store assistant said it was good for headaches. If I'd known it was catnip I wouldn't have got it."

"Yes, you would. You just can't resist experimenting."

"Not with drugs," Castle said heavily.

Beckett's eyes opened wide.

"Never, ever with drugs on someone else."

She blinked.

"I _saw_ what happened when drinks got spiked." He squirmed. "I'm not saying _I_ was totally clean all the time – but I never did it to anyone else." He suddenly had her full attention. He wriggled even more uncomfortably, ears pink. "I – er – had to get some of them out."

"Of jail – or of wherever you were?" she asked.

His ears went bright red.

"Where you were."

He nodded.

Her hand crept on to his shoulder. "How?"

"Some were...um...suggestible. Some...I pretended I wanted a good time. Who was going to argue with me?" Arrogance suffused his tone. Her hand dropped away. "And then I got them back to _their_ home." It returned. She never liked it when he behaved like the playboy superstar that Page Six would have him be. "So I wouldn't have doped you. If I'd thought it was catnip..."

"You'd have suggested we both try it."

"Uh...maybe?"

Beckett stayed still, not snuggling, not separating. Castle noted with disfavour that she was enveloped in a sloppy t-shirt, and that he was fully dressed. Neither seemed appropriate to the moment. He stripped down to his boxers and slipped under the quilt. His hands sneaked under the t-shirt and pulled her in close, producing a soft sigh and the removal of the t-shirt.

"I really didn't mean to get you high," he murmured.

"I know."

"Where've you been?"

"Out."

"Not the precinct – did you go to Central Park without me?" His hands clamped round her waist. "You did! You went and had all the fun of prowling round and terrifying lowlifes and I didn't! That's not fair!"

Beckett folded into herself.

Oh. Maybe that hadn't been the best thing to say.

"Is that what you do when you're upset?" No reply. "Look, stop _hiding_. I know I upset you, I said I didn't mean to, but stop hiding from me. I – you're _allowed_ to be upset in front of me, okay? Not just losing your temper – you do that plenty – but actually really in tears upset."

It was just as well he still had his hands on her waist. It meant that Onyx's attempt to leap off the bed could be foiled before it began.

"And turning into something that can't talk is cheating too. Stop hiding and just _tell_ me you're upset." Onyx monumentally failed to respond to that. Castle plucked her out of the sheets – she wouldn't rip her claws through her own sheets – and, sitting up against the pillows, tucked her into her favourite place on his shoulder and petted her.

"Silly cat," he soothed. "Hiding from me." The cat emitted a disgruntled growl-mew, which didn't exactly fill Castle with confidence in his tactics. He continued to stroke, which wasn't having much effect. Onyx might not have been running away, but she surely wasn't nestling in.

"Why do you do this?" he asked. "You know I'll find out that you're upset eventually, so why hide? You know you can lean on me. Just because you couldn't tell anyone the truth about being a cat – which is still the coolest secret _ever_ – you think you can't share anything difficult. Well, you shared being a cat with me – and made me one too, so you should share the rest of how you feel. If you couldn't trust me you'd never have sneaked into that alley." His fingers hadn't ceased to pet. "Just trust me, Kate."

Abruptly, human-Beckett arrived in his arms, her head on his shoulder just where Onyx had been – for a second, before she put a small but ominous distance between them.

"Trust goes both ways. You want me to trust you but then you sneak around to get answers without talking to me either." Castle opened his mouth. "I believe you about the tea. But... you've got a track record. You could have asked me about the t-shirts and natural fibres. You could have asked me about brushing and ear-petting. But you didn't. So..."

Castle got around to shutting his mouth. "But you don't tell me about it. You don't answer."

"You don't ask."

"Because you never answer."

It was Beckett's turn to close her mouth. Without answering.

It wasn't... Oh. He might have a point. She didn't confide. But it wasn't just about the cat: that had been just one more secret. It had been her father, and her – seen now – half-hearted relationships, and, let's face it, a woman in the man's world of the NYPD wasn't exactly going to admit to any weakness or ever be seen upset rather than angry, was she?

"No..." she said.

Castle's jaw dropped. "No? I so totally didn't expect you to say that!"

Onyx reappeared, jumped off the bed and hid under it.

"You're doing it again. Hiding."

She was. Because she was totally embarrassed by his reaction and she really just wanted him to go away right now so she could be embarrassed completely on her own. Hiding was a perfectly reasonable reaction.

Hiding, it turned out, was only a perfectly reasonable reaction if there wasn't a large, predatory panther on a mission to retrieve her. Castle-panther turned out to have a very long reach indeed, and Beckett-Onyx found herself being scooted across the floor courtesy of a very large paw, and then pounced upon to keep her in place. Worse, she couldn't wash off the dust bunnies which had evidently been breeding under her bed, because she was pinned down. If he'd made claw holes in her wooden floors _he'd_ be paying for the repairs.

Castle-panther lay Sphinx-like on the floor, regarding her smugly. It was quite ridiculously unfair that his paws were that wide and his claws that long. It was also unfair that she was on her back, with her stomach and throat exposed. That position did very strange things to her. She should be scared, but instead she was, er, aroused. And that _rat_ knew perfectly well that in any cat form her reactions would be totally different from her human reaction, which would be to kill him. Slowly.

His paw wasn't pressing on her, but it was very clear that she wasn't going anywhere. The huge panther bared his teeth, coughed as if laughing, and bent his head to nuzzle at her nose. She batted at his ears, and he coughed again, a little meaningfully. Without effort, he flipped her over, caught her into two large paws, and tucked her in so that their fur merged and she was perfectly enclosed: safe, warm and wholly nestled. He'd never done that before. She liked it. She felt...um...protected. Sheltered. She lay quiet, and enjoyed it: eyes closed, tail still, ears up.

Castle-panther nipped very carefully at her neck, and Onyx sighed and relaxed. She wasn't going to try to go anywhere.

Oh. No. That was not dignified. He was _not_ going to be allowed to do _that_ ever again. The panther had picked her up by the scruff of her neck – with his teeth! – just as if she were a cub, which was totally _not allowed_ , and deposited both of them back on the bed, with her nestled into his forepaws again and their ears touching. He emitted a satisfied purr deep in his chest, closed his eyes and was instantly asleep. Beckett-Onyx promptly followed him. Forbidding him ever to pick her up like that again would wait until the morning.

Onyx opened an eye, decided she didn't like it and shut the eye again. Mornings should be abolished. There was a nuzzle at her neck. Too bad. Too early. She curled herself up tightly and ignored the morning, the nuzzle, and the whole wide world.

That was unfair. Nuzzling had stopped. The warm fur around her had disappeared, and while she had her own warm fur, she'd liked the extra. She gave an unhappy noise, and tried to slide under the quilt. Castle's large hands pulled her out again. She flicked her tail crossly, and flattened her ears.

"Out you come," he coaxed. "I wanna pet you."

Oh. She supposed she could deal with being petted, as long as she didn't have to wake up or do anything. She allowed herself to be extracted, placed on his shoulder, and stroked as only Castle could stroke her: perfectly judged to be firm without pressing; gentle without being ineffectual.

"Now," he said, when she was purring and contented: curled lax on his lap where she had slithered, "why don't you change back so we can fix this and then" – he grinned lazily – "find something fun to do?"

She didn't want to change back, and there was nothing to fix except Castle's insatiable curiosity, which was unfixable without a full frontal lobotomy. She had considered it, but he'd likely lose all the other things that made him Castle, which _probably_ wasn't worth it. However, his hands were petting around her ears in a very provocative fashion, which left her inclined to provide some provocations of her own. She switched form.

"Well, _hello_ ," Castle oozed.

Ah. No t-shirt. Which had had its usual effect on Castle, whose eyes were dilated as wide as they could go and who'd clearly forgotten any idea of talking. There was only room for one idea in his head right now, and it had nothing to do with talking. Not that she could talk. Her mouth was otherwise engaged, as was his, and stroking was not confined to her cat form. He could stroke her human form equally excellently, and he was. She arched into his wicked hands and encouraged him.

Fairly shortly her hands became equally wicked, which was obviously all Castle's fault for setting a bad example. He shouldn't have wasted his time getting dressed, because it all came off again. As did her minimalist panties, with considerable – er – appreciation – along the way. And then he slid against her and then into her and then they didn't bother with thinking or talking any more.

"So," Castle said lazily, a broad hand on her waist to hold her close (and stop her running off and hiding again, though the panther had loved hunting her down and catching her), "how about a deal?"

"Deal?"

"Yeah. Deal. I won't sneak around to find things out, but you answer when I ask. Or tell me you don't want me to know," he added hastily.

There was a brief flicker of the pure black Siamese before Beckett returned. For a moment, she didn't say anything.

"Okay..." she said finally. "But if I don't want to answer or tell you to keep your nose out, you don't keep trying to find out."

"Okay..." Castle said, just as slowly. "I'll...well, I'll try not to."

"I'll try to answer."

"Okay." He smiled beautifully. "All fixed."

"Mm."

"Come here."

"Why?" she asked, provocatively. "I'm comfy right here." She snuggled down and closed her eyes peacefully.

"It's mid-morning. You can't go back to sleep."

"I'm a cat. I can sleep anytime."

"Explains a lot about how you run your cases and never seem to need to sleep at night."

"They call them catnaps for a reason."

"You can't be a cat in the bullpen – can you?" His eyes lit up. "Where are you hiding? You must be hiding somewhere or I'd have heard about the precinct cat. C'mon. You've got to tell me now."

She smiled, very cat-like. "Nope. I don't." His face fell. "But you can look for me. If you find me..." she trailed off, enticingly, "...then you get a prize."

"Hide and seek? I _love_ hide and seek."

"So do I," Beckett purred. She flicked a quick glance at the open bedroom door. "Catch me if you can," she teased, changed and flashed past him out of the door. Castle's panther was a crucial few, stunned, seconds behind her, by which time she'd disappeared. Of course, she had the advantage that she knew her apartment inside out, which, despite Castle's best efforts, he did not. (But he would. He surely would.)

He padded out of the bedroom, yawned – and changed back to close the door. He knew she wasn't in there, and now she couldn't get back in without changing herself. Back as a panther, he sat and sniffed the air. It didn't help. The whole apartment was Beckett/Onyx-scented, which he should have thought of. He looked around, eyes narrowed and the thrill of hunting thrumming through him; his claws flexed out and – when he realised – in again. Clawing Beckett was not a good plan.

Aha. Over there. A pile of cushions was suspiciously disarranged. He prowled sideways, sneaking up on the heap, pounced – and caught nothing but air and a stray feather. A derisive mew came from behind him, and he whipped round to see the tip of a black tail disappear under the couch. Well, he knew how to deal with her hiding under furniture. He swiped a huge paw underneath, from end to end. All he caught were dust bunnies.

He sat back on his haunches and considered. An idea inserted itself into his head. He slinked on to the couch, and lay there, still and absolutely silent. Beckett would never believe he could be patient, but his panther was far more patient when stalking than Castle-human, and besides, he could be patient when the reward would be so pleasurable.

He waited, and waited, and waited. Finally, a set of sable whiskers emerged from a small nook, followed by Onyx's elegant nose and ears. He hunkered down, and waited further. The rest of Onyx arrived, right to the tip of her tail. Still he waited, until she took a few delicate steps away from her hiding place.

And then he pounced from the couch, and landed right behind her on three feet; the fourth paw restrained to a gentle landing on her back rather than the instinctive blow. She miaowed crossly, and lay down, conceding.

"Got you," he said happily, once changed back again. He picked her up and petted her against his shoulder. "I win. What's my prize?"

A human Beckett slithered into his lap. Much more importantly, a _naked_ human Beckett had slithered into his lap. He deeply regretted having donned his boxers, and regretted it even more when she straddled him.

"Prize?" she husked. "You want a prize?" She wriggled. "I think that's quite hard." She wriggled again. "Mm. Yes."

Castle was quite definitely hard. Beckett was obviously inclined to play with her prey, which was entirely unfair since he'd won the chase. On the other hand, playful Beckett – playful _naked_ Beckett – wasn't so common that he'd take any risks of spoiling it, since playful naked Beckett was his best playmate ever.

"My prize is you," he growled, the panther's love of the chase and the catch underlying his words. "I caught you." His arms tightened around her, and she smiled.

"So you did. And here I am." She wiggled. "Here you are, too."

"So I am," Castle said lazily, "and I'm just considering what to do with you. So many options." He kissed her, which was always a good option to begin with, and was enthusiastically kissed in return. Hands wandered freely, petting became stroking became palming and rolling and sliding; mouths investigated and found delights; bodies heated and breath panted; and one dragged the other back to bed.

"I have an idea," Beckett breathed into Castle's oh-so-attentive ear.

"Mm? What sort of an idea? Having ideas is my job."

"No, that's having crazy theories." She smiled mischievously. "I think we need to share more."

"Yes? I mean, _yes_ , but what are you suggesting we share that we don't already?"

"Well..."

"What! Tell me, Beckett. It's not fair to tease me like that."

"When I...mmmm... _tease_ you, you'll know about it," she breathed.

"Just _tell_ me."

He pinned her down by leaning across her chest and drew his fingers threateningly over her midriff to the spot that he knew was hopelessly ticklish.

"Well..." she said again, and squeaked as his fingers moved. "Don't tickle! Not nice."

"Neither's not telling me your idea."

"Bully," she grumbled. "Okay. We should share that tea."

"Uh?"

"You think I'm going to be the only doped cat in our house?"

" _Our house_?" Castle gulped.

Beckett's jaw dropped as she realised what she'd said. She hadn't meant to put it quite like that.

"Our house?" he said again. "Uh...are you suggesting you should move into the loft? Because I'm totally up for that and I'll call the movers right now but since most of your shoes are already there I think we've got the main issue covered and who's going to take over this apartment" –

"We are."

"Uh? But... but what about my loft? I don't wanna" –

"We'll have that too."

"Uh?"

Beckett took pity on Castle's sex-addled brain. He wasn't usually that slow. "I was still working it out, but I thought that we could be mostly human at yours and keep here for being, well, not. All the time. Nobody's going to walk in on us here, and we could turn it into a place that's really cool for cats."

Castle gleeped. Words were beyond him. Beckett oofed.

"Need to breathe," she gasped. Oh. He loosened his grip on her and kissed her hard.

"Move in? Really? I've been waiting for you to get there for _months_."

"We've only been...um..."

"Dating?"

"I guess – for six months."

He coloured. "Well. Anyway." He kissed her again, rather than sticking his foot in his mouth. "That's a great idea," he said after he lifted off.

"I know."

"Smugness isn't attractive."

Beckett merely smiled. Smugly.

"So when are we going to do it?"

"Soon?" Beckett said, a little uncertainly.

"How about tomorrow?"

She supposed that that was soon. "Don't you think it might be better to give your family more than twelve hours' warning?"

Castle pouted. "I guess. Next week, then."

Beckett, not unusually, felt as if she'd been caught up in the enthusiastic Castle-tornado.

"It'll be great," he bounced. "What do you want here to be like?"

"Cushions, low couches, rugs... a much taller scratching post."

"Why?"

"Panther. You like being a panther. I like being a cat. You need a taller post – or you'll be caught by Animal Control in Central Park ripping up their trees."

"Okay."

"But most importantly..." she paused and grinned mischievously.

"What?"

"A kettle, a teapot, and two teacups."

"Uh?"

"The first thing that's moving here is the catnip tea."

 _ **Fin.**_

* * *

 _Thank you to all readers and reviewers._


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